Performing Department
(N/A)
Non Technical Summary
Extreme temperatures that deviate from seasonal norms are increasing in frequency because of climate change. These changes will increase the risks of devastating crop losses, like those experienced for apple and pear crops over the last two decades. These losses urgently need to be reduced. However, our knowledge of apple and pear responses to temperatures is insufficient. Our current knowledge is largely derived from few cultivars that are now less commercially relevant. The industry needs mitigation strategies for current cultivars and knowledge to quickly assess new cultivars to determine if they are suitable for future climates. Goals 1 and 2 deliver management strategies that reduce risk of losses to extreme temperatures based on a better understanding of the physiological responses to extreme temperatures for economically important apple cultivars. These goals will alsoallow for the selection forkey traits affecting responses to extreme temperatures.Goal 3 will provide cost-benefit analysis that increases grower adoption of management strategies tested in Goals 1 and 2. It will also develop predictive models for risks of temperature-related losses in the future under climate change. Goal 4 will integrate research personnel with stakeholders to develop unified Extension programming that prepares the pome fruit industries in the U.S. for the challenges of climate change. This project will help sustain the U.S. as a leader in pome fruit production, strengthening the rural economy and providing consumers with a consistent supply of quality fruit produced in efficient and sustainable ways.
Animal Health Component
0%
Research Effort Categories
Basic
20%
Applied
50%
Developmental
30%
Goals / Objectives
GoalsReduce apple and pear losses from current and future extreme temperature events by supporting growers to select the best mitigation strategies and new cultivars that will succeed in a changing climate1.Reduce losses to apple and pear productivity and health from low temperature stress.2. Reduce the negative impact of high temperatures during summer/fall on fruit quality in pome fruit.3. Model the risks and economic impacts of temperature extremes to inform decision making by commercial apple and pear producers.4. Develop nationwide Extension programming to help growers manage orchard responses to adverse temperatures and prepare them for the effects of climate change on production.
Project Methods
Goal 1 -Reduce losses to apple and pear productivity and health from low temperature stress Here, we will characterize the phenotypic plasticity, transcriptomic response, and genetic architecture of winter physiology in pome fruit and develop management strategies that reduce losses.Objective 1.1. Assess cultivar-specific cold hardiness patterns and management strategies to reduce losses from cold temperature stress for apple and pearTask 1.1.1: Measure seasonal hardiness changes in apple and pear cultivarsTask 1.1.2: Characterize the impact of variable freeze damage on apple shoot recovery and mortality.Task 1.1.3: Evaluate strategies to increase flower bud cold hardiness during spring frost for current apple and pear cultivarsObjective 1.2: Characterize physiological changes in flower buds and stems during acclimation, dormancy, deacclimation, and budbreak in apple and pearTask 1.2.1. Measure cold hardiness and dormancy status of apple flower budsTask 1.2.2: Measure cold hardiness, assess dormancy status, and investigate transcriptional profiles of pear flower budsTask 1.2.3: Measure effects of snow cover insulation on scion and rootstock cold hardiness and associated gene expressionObjective 1.3: Unravel the genetic control of chilling requirement, budbreak, and bloom time for appleTask 1.3.1: Characterize phenotypic variation in scion chilling requirements among segregating rootstock linesTask 1.3.2: Evaluate engineered rootstocks with enhanced ABA synthesis for their ability to delay scion budbreakTask 1.3.3: Determine genetic control and variability in budbreak and bloom time in apple scionsGoal 2 -Reduce the negative impact of high temperatures during summer/fall on fruit quality in apple and pear.Emerging tools for managing these issues will be tested across all major pome fruit growing regions in collaboration with grower partners. By understanding how heat affects fruit quality and focusing on sunburn and red color development, more effective models and management practices can be adopted that minimize these losses. Furthermore, the identification of genetic and transcriptional control of sunburn and red color development in segregating populations will support the selection of new cultivars better suited to high temperatures.Objective 2.1: Assess agronomic strategies that enhance red color and fruit quality or reduce fruit sunburnTask 2.1.1: Test plant growth regulator enhancement of red color and fruit quality for 'Honeycrisp' applesTask 2.1.2. Test the use of partial defoliation to improve red color and fruit quality in contrasting environmentsTask 2.1.3. Conduct applied trials on netting retraction, low volume evaporative cooling, and protectant sprays for sunburn mitigationTask 2.1.4. Assess pear sunburn risk under high and low tree densitiesObjective 2.2: Determine fruit physiological responses to high temperatures: acclimation and red color development in appleTask 2.2.1. Characterize apple fruit acclimation to high temperaturesTask 2.2.2 Quantify the impact of preharvest temperature on apple red color development and fruit qualityObjective 2.3: Uncover the genetic control of fruit sunburn susceptibility and red color development in apple Task 2.3.1. Characterize genetic control of fruit sunburn susceptibilityTask 2.3.2. Characterize genetic control of red color developmentGoal 3: Model the risks and economic impacts of temperature extremes to inform decision making by commercial apple and pear producers.In year 1, we will use existing data sets that can be immediately used for targeted model development, and in years 2-4, data generated from Goals 1 and 2 will be used to update models. These models will support economic cost-benefit analyses for management strategies identified in Goals 1 and 2. Tools and analyses will inform growers of risks for losses, guide risk management strategies, provide variety suitability maps, inform crop insurance products for apple and pear production, and feed into the Extension activities described in Goal 4.Objective 3.1: Develop and refine temperature-based predictive models for horticulturally relevant variables. Task 3.1.1. Assemble a database for model development and develop a software workflow pipeline.Task 3.1.2. Develop and iteratively refine predictive models for economically important variables related to heat and cold stressObjective 3.2: Quantification of current production risks and cost-benefit analysis for cultivar choices and mitigation strategies.Task 3.2.1. Conduct cultivar and management-specific spatial assessments of risks of losses from adverse temperaturesTask 3.2.2. Perform cost-benefit analyses of management strategies that reduce losses from adverse temperatures for current conditionsObjective 3.3: Prediction of future risks, their economic implications, and optimal risk management strategies under near future climate change scenarios.Task 3.3.1. Develop regional risk assessment tools for future apple and pear productionTask 3.3.2. Identify key combinations of temperature-related traits that reduce risk for losses under future climate conditionsTask 3.3.3. Conduct cost-benefit analyses of cultivar-specific management strategies that reduce losses caused by adverse temperatures under future climate conditionsGoal 4. Develop nationwide Extension programming to help growers manage orchard responses to adverse temperatures and prepare them for the effects of climate change on production.The development of national Extension programming will result in an apple and pear industry more prepared to face adverse weather events for fruit they grow now. The Extension team will facilitate regional knowledge transfer of effective management practices to limit losses caused by cold and heat stress. New knowledge acquired on cultivar-specific risks and management practices that reduce losses for producers will be communicated to the broader U.S. pome fruit industry. Predictive models will provide growers with information and decision-aid tools to select management practices and suitable cultivars for new orchards, while also producing scion and rootstock cultivar recommendations for future climates.Objective 4.1: Outreach to growers and other stakeholdersTask 4.1.1: Conduct a nationwide survey to assess risk thresholds for losses caused by adverse temperatures which are often difficult to quantify.Task 4.1.2: Coordinate regional field trials and demonstrations for applied management strategies to reduce temperature-related lossesTask 4.1.3: Connect Extension/outreach efforts for this project with national/regional Extension meetings and orchard toursObjective 4.2: Tools and training for using management practices and predictive toolsTask 4.2.1: Conduct fruit schools for cold and heat stress management in apple and pearTask 4.2.2: Produce decision-aid and climate tools that improve region-specific management strategies and cultivar selectionTask 4.2.3: Publish durable Extension products